Analysis TAPPI methods

Fiber Analysis. Paper may be composed of one or several types of fibers, eg, animal, vegetable, mineral, and synthetic (see Eibers). Paper is generally composed of woody vegetable fibers obtained from coniferous (softwood) and deciduous (hardwood) trees. QuaUtative and quantitative methods have been developed to determine the fibrous constituents in a sheet of paper (see TAPPI T401). However, the proliferation in the number and types of pulping processes used have made the analysis of paper a much more complex problem. Comprehensive reviews of the methods are given in References 20 and 23. 

Analysis of certain papers requires special treatment before they can be disintegrated properly. Papers containing synthetics, tars, asphalt, mbber, viscose, or wet-strength resins must be analyzed individually (see TAPPI T401) (20). Dyes or colors must be removed from highly colored papers before examination. The method of dye removal depends on the type of dye. 

Tappi standard T 223 outlines the procedure for pentosan analysis. Briefly, wood meal is boiled in 3.85 N HCl with some NaCl added. Furfural is generated and distilled into a collection flask. The furfural is determined colorimetrically with orcinol-iron(III) chloride reagent. Another method also generates furfural, and the furfural is determined gravimetrically by precipitation with 1,3,5-benzenetriol. These and other methods of pentosan analysis are described and discussed in Browning s book (36). 

Sugar separation by GC requires the preparation of volatile derivatives. Tappi Test Method T 249 pm-75 uses the alditol acetate derivitization (40). Peracetylated aldonitrile (4J) or trimethylsilane (42, 43) derivatives can also be prepared and separated by GC. Wood sugar analysis by GC may be useful for specialized problems, but the derivitization steps make it a time-consuming method for routine work. 

Commercial trade in chemical celluloses is assisted by the definition of standard methods of analysis. Extensive collections of quality-defining protocols have been assembled by ISO, the International Standards Organization ASTM, the American Society for Testing Materials TAPPI, the Technical Association of the Pulp and Paper Industry (of USA) DIN (German Industrial Norms) and many others. 

Method Standardization. Hofimann (2) discussed the need to standardize the methods of analysis in 1981. He recommended the use of the standard procedures designed for analysis of fresh wood by the Technical Association of the Pulp and Paper Industry (TAPPI). Although some minor problems with the methods would be expected because of modification of degraded chemicals, he felt that the procedures would give an adequate characterization of archaeological wood. Hofimann encouraged the use of these analytical methods so that in the course of time enough analysis would be done to confirm relationships between analysis and response to specific treatments. 

Analysis The chemical analysis of wood is carried out by ASTM (American Society for Testing and Materials) and TAPPI (Technical Association of the Pulp and Paper Industry) standards. These methods can be summarized as in Table 1 following milling to 40 mesh (400 pm) and air drying. 

TAPPI (1987) Official Test Method from the Technical Association of the Pulp and Paper Industry - TAPPI Analysis of Pulping Liquors by Suppressed Ion Chromatography. T699 om-87. 

The high quality casein described above is not necessary for all industrial adhesives. The important features for many adhesives are minimal viscosity variations and predictable performance in a formula. For some applications the particle size is important, and either the normal 30 mesh casein is specified, or for many processes not using heat for solubility, a 60 or an 80 mesh. Tables 1 and 2 give typical analyses for the industrial casein currently in use in this country. Standard methods for testing casein appear in the Encyclopedia of Industrial Chemical Analysis, Vol. 9, 1970, and in TAPPI Monograph 35, 1974. ... 

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